title: Long-term follow-up of simultaneous guided bone regeneration using native and cross-linked collagen membranes over 6 years.
abstract: OBJECTIVE
  To investigate the impact of a cross-linked- (VN) collagen membrane on the long-term stability of peri-implant health over 6 years.
  
  
  METHODS
  Vestibular dehiscence-type defects at titanium implants (19 patients, 19 implants) were augmented using a natural bone mineral and randomly allocated to either VN or a native collagen membrane (CM) and left to heal in a submerged position for 4 months. Clinical parameters (i.e. Bleeding on Probing-BOP, probing pocket depth-PD, mucosal recession-MR) were recorded at 4 and 6 years after prosthesis installation.
  
  
  RESULTS
  At 4 and 6 years, both VN and CM revealed comparable mean BOP, PD and MR values at both vestibular and oral aspects. Changes in these parameters from 4 to 6 years were minimal (vestibular aspect-VN: -3.3 ± 48.2%, -0.1 ± 0.5 mm, -0.1 ± 0.3 mm; CM: -1.8 ± 33.7%, 0.0 ± 0.4 mm, -0.1 ± 0.7 mm) and not significantly different between groups. At 6 years, the incidence of mucositis and peri-implantitis was comparable in both groups (VN: 60.0% and 20.0%; CM: 33.3% and 33.3%).
  
  
  CONCLUSIONS
  In conclusion, the present follow-up observation failed to identify any beneficial impact of VN over CM on peri-implant health at 4 and 6 years.
authors.affiliation: Department of Oral Surgery, Heinrich Heine University, Düsseldorf, Germany.
authors.forename: Frank
authors.initials: F
authors.lastname: Schwarz
authors.forename: Andrea
authors.initials: A
authors.lastname: Hegewald
authors.forename: Narja
authors.initials: N
authors.lastname: Sahm
authors.forename: Jürgen
authors.initials: J
authors.lastname: Becker
mesh_terms: D018786:Bone Substitutes / Q000494:pharmacology; D003094:Collagen / Q000494:pharmacology*; D015921:Dental Implants; D004311:Double-Blind Method; D005260:Female; D005500:Follow-Up Studies; D016557:Guided Tissue Regeneration, Periodontal / Q000379:methods*; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008567:Membranes, Artificial; D008875:Middle Aged; D010512:Periodontal Index; D011446:Prospective Studies; D012307:Risk Factors; D013529:Surgical Wound Dehiscence / Q000209:etiology / Q000628:therapy*; D014025:Titanium; D016896:Treatment Outcome
chemical_list: D018786:Bone Substitutes; D015921:Dental Implants; D008567:Membranes, Artificial; D003094:Collagen; D014025:Titanium
keywords: bone regeneration; bone substitutes; clinical research; clinical trials; guided tissue regeneration